South Korea is entering potentially one of the most momentous weeks in its recent political history, with impeachment looming for President Park Geun-hye as ruling party dissenters align with the opposition in a strengthening effort to force her out.

Anti-Park lawmakers in the ruling Saenuri Party said Monday that about 35-40 of them will vote Friday to impeach Park, who is embroiled in an explosive political scandal. Those votes, when combined with 172 from opposition and anti-Park independent lawmakers, should be enough to impeach her.

If impeached, Park's presidential powers will be suspended until the country's Constitutional Court determines whether to formally unseat her. The court has up to 180 days to decide.

The decision by the anti-Park ruling party lawmakers came after hundreds of thousands of people turned up for a rally in Seoul on Saturday calling for Park's ouster, the sixth straight weekend of demonstrations. Park made a conditional resignation offer last week, saying she would stand down if parliament works out a stable power transfer, but the opposition described it as a stalling tactic.

The scandal centers on allegations that Park let her longtime friend Choi Soon-sil manipulate government affairs from the shadows and extort money from businesses. Park has denied most of the allegations, though she acknowledged that she got help from Choi, who has never held a government job, in editing her speeches and with unspecified “public relations” issues.

Prosecutors have indicted Choi and two of Park's ex-aides. Park, who has immunity from prosecution while in office, has refused to meet with prosecutors.

Lawmakers are holding hearings to separately look into the scandal. Heads of businesses allegedly involved in the scandal, including Samsung and Hyundai conglomerates, were scheduled to attend a hearing Tuesday. Choi has refused to testify at her session Wednesday, according to officials at the National Assembly, South Korea's legislature.

A coalition of opposition and independent lawmakers submitted a motion on Park's impeachment over the weekend, accusing her of violating the constitution and undermining democracy. A National Assembly official is to report the motion to a plenary session on Thursday, a formal procedure that can force an impeachment vote within 72 hours.

The opposition wants an impeachment vote on Friday, the final day of the current parliamentary regular session.